Device for image based services

ABSTRACT

A device is provided having: a camera for capturing an image by capturing a repetitive series of a set of frames; wherein the camera comprises a first group of camera settings associated with detecting Visible Light Communication and a second group of camera settings not associated with detecting Visible Light Communication; wherein said set of frames comprises a first subset of frames and a second subset of frames, wherein each subset comprises at least one frame; a processor configured to switch the camera periodically between the first group of camera settings and the second group of camera settings for capturing the image by capturing each first subset of frames of the repetitive series of the set of frames with the first group of camera settings and each second subset of frames of the repetitive series of the set of frames with the second group of camera settings.

CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is the U.S. National Phase application under 35 U.S.C.§ 371 of International Application No. PCT/EP2019/051479, filed on Jan.22, 2029, which claims the benefit of European Patent Application No.18153838.0, filed on Jan. 29, 2018. These applications are herebyincorporated by reference herein.

FIELD OF THE INVENTION

The invention relates to a device for image based services, wherein thedevice comprises a processor and a camera for capturing an image. Theinvention further relates to a method for image based services, themethod being performed by a device comprising a camera and a processor.The invention further relates to a computer program product performingsaid method.

BACKGROUND OF THE INVENTION

An image based service may be defined as a service and/or an applicationwhich is enabled by images recorded with an image sensor, such as e.g. acamera. Image based services become more widespread, because imageprocessing techniques and computing intelligence allow image data to beanalyzed more effectively, more accurately, more efficiently, and moreelaborately. Known image based services may comprise Augmented Reality,object recognition, emotion detection, image analytics, and/or indoorpositioning based on coded light, e.g. Visible Light Communication(VLC). Thus, devices become ever more equipped with image sensors, suchas e.g. cameras.

Visible Light Communication (VLC) refers to techniques wherebyinformation is communicated in the form of a signal embedded in thevisible light emitted by a light source. The signal is embedded bymodulating a property of the visible light, typically the intensity,according to any of a variety of suitable modulation techniques. Basedon the modulations, the information embedded in the light can bedetected using any suitable light sensor, such as e.g. a photodiode anda camera. Detecting and/or decoding of such information is for exampledescribed in EP3105868B1. Similarly, coded light may refer to the sameprinciples, but may also include the non-visible spectrum of light aswell, such as LiFi.

The present invention relates to a device for image based services. Sucha device, and a corresponding system, may e.g. be known fromUS2005/0265731A1, in which a short range wireless communication systemis provided using a camera sensor module. The camera sensor modulesenses and converts optical signals into electrical signals andtransfers the sensed signals to an image signal processor during acamera mode, but additionally sends the sensed signals to a demodulatorduring a communication mode. As the camera sensor module performscommunication functions, such a system may enable Visible LightCommunication.

Although such a system may enable Visible Light Communicationeffectively, it is nevertheless limited in application for image basedservices, because it cannot simultaneously enable the camera sensormodule for Visible Light Communication and other image based services,such as e.g. Augmented Reality.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved device for imagebased services. Thereto, the invention provides a device for image basedservices comprising: a camera for capturing an image by capturing arepetitive series of a set of frames; wherein the camera comprises afirst group of camera settings associated with detecting Visible LightCommunication and a second group of camera settings not associated withdetecting Visible Light Communication; wherein said set of framescomprises a first subset of frames and a second subset of frames,wherein each subset comprises at least one frame; a processor configuredto (i) switch the camera periodically between the first group of camerasettings and the second group of camera settings for capturing the imageby capturing each first subset of frames of the repetitive series of theset of frames with the first group of camera settings and each secondsubset of frames of the repetitive series of the set of frames with thesecond group of camera settings; (ii) enable image based services basedon at least one frame of the first subset of frames and/or at least oneframe of second subset of frames; wherein said first subset of framescomprises a first number of frames and said second subset of framescomprises a second number of frames; wherein the processor is furtherconfigured to increase or decrease said first number of frames and/orsaid second number frames based on a characteristic detected in theimage and/or based on a sensor input to the device.

Such a device is using a concept of switching the camera periodicallybetween the first group of camera settings and the second group ofcamera settings for capturing the image. Each first subset of frames ofthe repetitive series of the set of frames is hereby captured with saidfirst group of camera settings. The first group of camera settings isparticularly suitable for detecting Visible Light Communication.However, when camera settings are particularly suitable for detectingVisible Light Communication, said camera settings may typically not besuitable for accurately performing other image based services, which maynot be associated with detecting VLC; because the detection of VLC ise.g. typically done at specific camera settings such as at least one ofthe group of underexposure, high ISO and low resolution. Hence, thesecond group of camera settings may be associated with another imagebased service, which may be opposite to the camera settings associatedfor detecting VLC. Therefore, the camera of the device according to theinvention comprises a second group of camera settings not associatedwith detecting VLC. Such camera settings may at least be overexposure,low ISO and high resolution, as—opposite to the requirement of detectingVLC—specific details of objects in an image need to be identifiable forother image based services such as Augmented Reality, ObjectRecognition, emotion detection, iris scanning, etc.

Thereto, the device according to the invention comprises a processorconfigured to switch the camera periodically between the first group ofcamera settings and the second group of camera settings for capturingthe image by capturing each first subset of frames of the repetitiveseries of the set of frames with the first group of camera settings andeach second subset of frames of the repetitive series of the set offrames with the second group of camera settings. This is advantageous.

The effect of said switching is that the camera may capture an image,wherein each first subset of frames of the repetitive series of the setof frames may particularly be suitable for detecting VLC, whereas eachsecond subset of frames of the repetitive series of the set of framesmay particularly be suitable for image based services other than VLC,e.g. phrased as another image based services. Hence, two different imagebased services—one being VLC—may be enabled by only using a singlecamera comprised within a device according to the invention, whereineach of said two different image based services may operate with adesired camera setting suitable for their purpose. This is a clearadvantage, and fulfills a clear need in the developing technical fieldsof image based services, visible light communication and imageanalytics.

As a result, a characteristic detected in the image may provide a cuefor the device to capture the image with the first and/or second groupof settings with higher and/or lower number of frames. This ensures anadaptive system, that is a device which may advantageously adapt theframerate of detecting the image with the first and/or second group ofsettings accordingly.

In an embodiment, the first group of camera settings comprises anexposure time of at most 1/1000 seconds, wherein the second group ofcamera settings comprises an exposure time of at least 1/1000 seconds.

As partly mentioned before, such a device is using a concept ofswitching the camera periodically between the first group of camerasettings and the second group of camera settings for capturing theimage. Each first subset of frames of the repetitive series of the setof frames is hereby captured with said first group of camera settings.As the first group of camera settings comprises an exposure time of atmost 1/1000 seconds, the first group of camera settings is particularlysuitable for detecting VLC. Namely, the image captured by the firstsubset of frames will be underexposed; wherein underexposing typicallyresults in a darkened image in which only the bright areas are moredistinct. Thus, an image of a light source emitting a modulated lightsignal—e.g. VLC or coded light—may be detected more accurately, and themodulated light signal may be received more effectively. Setting thecamera to the first group of camera settings is therefore a clearadvantage for detecting VLC and/or coded light.

However, said first group of camera settings is typically not suitablefor accurately performing other image based services, which may not beassociated with detecting VLC. Hence, the second group of camerasettings may be associated with another image based service. Forexample, as the first group of camera settings comprise an exposure timeof at most 1/1000, the image captured by the first subset of frames willbe underexposed and hence prevent capturing and/or analyzing a detail inthe image required for e.g. Augmented Reality, object recognition,emotion detection, etc. Such a detail may for example be an anchoringpoint for Augmented Reality, which may not be captured well by the imagedue to the underexposing. Such a detail may for example be a facialfeature required for emotion detection, such as imaging an iris of aneye, which may not be captured well by the image due to theunderexposing. Therefore, the camera of the device according to theinvention comprises a second group of camera settings not associatedwith detecting VLC, wherein said second group of camera settingscomprises an exposure time of at least 1/1000 seconds.

Thereto, the device according to the invention comprises a processorconfigured to switch the camera periodically between the first group ofcamera settings and the second group of camera settings for capturingthe image by capturing each first subset of frames of the repetitiveseries of the set of frames with the first group of camera settings andeach second subset of frames of the repetitive series of the set offrames with the second group of camera settings.

The effect of said switching is that the camera may capture an image,wherein each first subset of frames of the repetitive series of the setof frames may particularly be suitable for detecting VLC, whereas eachsecond subset of frames of the repetitive series of the set of framesmay particularly be suitable for image based services other than VLC,e.g. phrased as another image based services. Hence, two different imagebased services—one being VLC—may be enabled by only using a singlecamera comprised within a device according to the invention, whereineach of said two different image based services may operate with adesired camera setting suitable for their purpose. This is a clearadvantage, and fulfills a clear need in the developing technical fieldsof image based services, visible light communication and imageanalytics.

For example, in a non-limiting example, the present invention may enablea camera device to provide Indoor Positioning based on VLC, whilesimultaneously providing face recognition and/or emotion detection—e.g.based on imaging of an iris of an eye. Enabling said two different imagebased services with a single camera is advantageous, e.g. because thecurrent state of the art does not allow to perform said servicessimultaneously by a single camera capturing an image; and because it mayallow many applications, amongst others simultaneously mapping emotionsto locations in a retail environment.

Here, said camera for capturing an image may in examples be phrased as acamera for recording an image.

Here, in examples, said detecting VLC (coded light) may comprise:detecting the light source emitting the coded light signal,distinguishing the light source emitting the coded light signal fromother light sources and/or other light sources emitting a differentcoded light signal, receiving a larger footprint of the light sourceemitting the coded light signal at the camera cell, distinguishing alight source emitting a coded light signal from its surroundings,ensuring a faster detection/reception of the emitted code, etc.

Here, Visible Light Communication may refer to modulated light visibleto the camera, such as a spectrum covered by a camera, and notnecessarily or solely the spectrum visible to the human eye.

Here, according to an alternative aspect of the invention, saiddetecting Visible Light Communication may be mutatis mutandis detectingCoded Light. Coded light may hereby be emitted by a light source, alamp, or a luminaire. Thus, according to said alternative aspect of theinvention, the camera may comprise a first group of camera settingsassociated with detecting Coded Light and a second group of camerasettings not associated with detecting Coded Light. The effects andadvantages of the present invention including the feature of detectingVLC may mutatis apply to detecting CL.

Said device for image based processing may be part of a smartphone, atablet, a smartwatch, a wearable device, a smart glass, an augmentedreality goggle, virtual reality device, heads-up display, or anavigation device. Said device may comprise a transceiver to communicatewith other devices or a back-end computing device, wherein part of theprocessing, e.g. the post-processing or image analytics employed to theimage, may be performed at said other devices or the back-end computingdevice. Said communication may be by a wireless connection such asWi-Fi, Bluetooth, VLC, LoRa, LiFi, ZigBee or RF.

Said image being captured by the camera may be a set of photographs or avideo. The processor may comprise computational power to decode a codecomprised within the image, such as a code related to coded light orVLC. The processor may comprise a local memory for storing information,such as the image. The processor may comprise computational power toperform image processing.

Said camera may be suitable for detecting coded light, and/or VLC. Oneway to detect VLC is e.g. using a rolling shutter type camera. Suchcameras are often integrated into mobile devices such as smartphones ortablets. In a rolling-shutter camera, the camera's image capture elementis divided into a plurality of lines (typically horizontal lines, i.e.rows) which are exposed in sequence line-by-line. That is, to capture agiven frame, first one line is exposed to the light in the targetenvironment, then the next line in the sequence is exposed at a slightlylater time, and so forth. Alternatively, in some examples, e.g.depending on the format for receiving VLC, the camera may be a globalshutter camera.

In an embodiment, the device may comprise a display for displaying theimage, wherein the display is arranged to display the image in afront-facing direction, wherein the camera is a front-facing cameradirected towards the front-facing direction for capturing an image. Suchan embodiment is advantageous, because the front-facing camera maycapture an image of a user looking at the display of the device, whichmay enable image based applications such as e.g.: emotion detection ofsaid user, while simultaneously being able to detect light sourcesemitting coded light or VLC behind the user, e.g. on a ceiling; gesturedetection, face recognition, iris scanning, etc.

As mentioned, the first group of camera settings comprises an exposuretime of at most 1/1000 seconds. In embodiments, the first group ofcamera settings may comprise an exposure time of at most 1/1500 seconds,at most 1/2000 seconds, at most 1/3000 seconds, at most 1/4000 seconds,or between at least 1/2000 seconds and at most 1/1000 seconds. Since ashorter exposure time renders more contrast between bright areas anddark areas within a captured image, a bright feature such as a lightsource may become more distinct in the image in comparison to the lightsource surroundings by decreasing the exposure time. Such a distinctionis therefore advantageous in detecting VLC or coded light signalsemitted by a light source, such as a light source comprised within aluminaire. Said exposure time ranging between at least 1/2000 secondsand at most 1/1000 seconds may be particularly advantageous for use inVisible Light Communication based on e.g. current Philips practice.Namely, said exposure time is related to the symbol clock of the devicefor detecting a Visible Light Communication signal. See also below. Thenotion of symbol clock of the device is known to a person skilled in theart, because e.g. a VLC signal may be encoded with a symbol rate of 1kHz, 2 kHz, or e.g. 4 kHz. Here, for example, the exposure time of atmost 1/1000 seconds therefore corresponds with halve of a 2 kHz rate ofthe symbol clock, which 2 kHz rate is in agreement with current Philipspractice. Moreover, said exposure time of at most 1/2000 secondssimilarly agrees with said symbol clock of devices used in the currentPhilips practice; e.g. indoor positioning based on VLC.

Furthermore, as mentioned, the second group of camera settings comprisesan exposure time of at least 1/1000 seconds. In embodiments, the secondgroup of camera settings may comprise an exposure time of at least 1/800seconds, at least 1/500 seconds, at least 1/250 seconds, at least 1/100seconds, or between at least 1/1000 seconds and at most 1/500 seconds.Due to a higher exposure time, details in an image captured with saidhigher exposure time may be visible. Such details may be relevant forimage based processing such as Augmented Reality, object recognition,emotion detection, etc.

In alternative embodiments, said exposure time may depend on the rate ofexposure of a mechanical filter positioned in the view of the camera.

Yet alternatively, in examples, the first group of camera settingscomprises a first exposure time, and the second group of camera settingscomprises a second exposure time, wherein the first exposure time isshorter than the second exposure time. Moreover, in a furtherembodiment, the first exposure time is at least 1/500 seconds shorterthan the second exposure time. This will ensure a clear differencebetween the first group of camera settings and the second group ofcamera settings, such that the first group of camera settings are moresuitable for detecting VLC, whereas the second group of camera settingsis oppositely more suitable for other image based services.

As known to a person skilled in the art: Data may be modulated intolight by means of a technique such as amplitude keying or frequencyshift keying, whereby the modulated property (e.g. amplitude offrequency) is used to represent channel symbols. The modulationtypically involves a coding scheme to map data bits (sometimes referredto as user bits) onto such channel symbols. An example is a conventionalManchester code, which is a binary code whereby a user bit of value 0 ismapped onto a channel symbol in the form of a low-high pulse and a userbit of value 1 is mapped onto a channel symbol in the form of a high-lowpulse. Another example is the Ternary Manchester code. Moreover, forexample a coded light signal may be encoded with a symbol rate of saidsymbols being 1 kHz, 2 kHz or 4 kHz.

Here, said exposure time may also be correlated to a property of thecamera or the device. It may for example be advantageous to correlatethe exposure time to the decoding scheme of the Visible LightCommunication and/or coded light messages. See for example EP3105868B1for decoding VLC and/or coded light messages. Hence, in an embodiment,the first group of camera settings may comprise an exposure timeproportional to a symbol clock of the device, the symbol clock beingrelated to detecting the Visible Light Communication.

In further embodiments, the first group of camera settings may comprisean exposure time equal to at least a quarter or at least halve of asymbol clock of the device, the symbol clock being related to detectingthe Visible Light Communication. Hence, relating the properties ofdetecting VLC, which is the rate of the symbol clock of the device, tothe exposure time of the camera of the device, this will enable toselect an advantageous exposure time for detecting VLC in particular.

An ISO value (of a camera device) may also influence the effectivenessof detecting VLC, while adversely influencing the effectiveness of otherimage based services applications, such that said switching according tothe invention is advantageous. Hence, in an embodiment, the first groupof camera settings may comprise an ISO value of at least 400. As thefirst group of camera settings comprises an ISO value of at least 400,the first group of camera settings is particularly suitable fordetecting VLC. Namely, the camera capturing the image in the firstsubset of frames comprising an ISO value of at least 400 may be moresensitive to light. Thus, an image of a light source emitting amodulated light signal—e.g. VLC or coded light—may be detected moreeffectively due to the increased footprint of the light source (e.g.comprising a ‘halo’ in the captured image). Thus, the modulated lightsignal may be received more effectively. Setting the camera to the firstgroup of camera settings is therefore a clear advantage for detectingVLC and/or coded light. However, said first group of camera settingscomprising an ISO value of at least 400 is typically not suitable foraccurately performing other image based services, which may not beassociated with detecting VLC. For example, as the first group of camerasettings comprise an ISO value of at least 400, the image captured bythe first subset of frames will comprise more granularity and noise,hence limiting image quality and preventing to capture and/or analyzedetails in the image. Such details may e.g. be required for AugmentedReality, object recognition, emotion detection, etc. Hence, in anembodiment, the second group of camera settings may comprise an ISOvalue of at most 400. Thus, considering the above, said switchingaccording to the invention is advantageous to improve image basedservices associated with detecting VLC and simultaneously improve otherimage based services not associated with detecting VLC, both with asingle camera.

Alternatively, the first group of camera settings may comprise an ISOvalue of at least 800, at least 1600, or at least 3200. Alternatively,the second group of camera settings may comprise an ISO value of at most400, at most 200, at most 100, at most 50, or equal to 50, or an autoISO not extending beyond a value of 400.

Resolution of capturing the image with the camera may also influence theeffectiveness of detecting VLC, while adversely influencing theeffectiveness of other image based services applications, such that saidswitching according to the invention is advantageous. Hence, in anembodiment, the first group of camera settings may comprise a resolutionof at most 1 megapixel, wherein the second group of camera settings maycomprise a resolution of at least 1 megapixel. As the first group ofcamera settings comprises a resolution of at most 1 megapixel, the firstgroup of camera settings is particularly suitable for detecting VLC.Namely, an image of a light source emitting a modulated lightsignal—e.g. VLC or coded light—may be detected more effectively, becausea higher resolution slows down VLC detection due to the increaseprocessing time (and increased depletion of battery power). A resolutionof at most 1 megapixel is particularly suitable for detecting VLC.Setting the camera to the first group of camera settings is therefore aclear advantage for detecting VLC and/or coded light. However, saidfirst group of camera settings comprising a resolution of at most 1megapixel is typically not suitable for accurately performing otherimage based services, which may not be associated with detecting VLC;because such image based services may require more and more resolutionto improve the detection of detail. Such a detail may e.g. be requiredfor Augmented Reality, object recognition, emotion detection; forexample, detecting an iris of an eye or a change in facial features.Thus, considering the above, said switching according to the inventionis advantageous to improve image based services associated withdetecting VLC and simultaneously improve other image based services notassociated with detecting VLC, both with a single camera.

Alternatively, the first group of camera settings may comprise aresolution of at most 0.8 megapixel, or at most 0.5 megapixel.Alternatively, the second group of camera settings may compriseresolution of at least 2 megapixel, at least 4 megapixel, at least 8megapixel, at least 10 megapixel, or at least 12 megapixel, or betweenat least 4 megapixel and at most 12 megapixel.

A focus of a camera in capturing the image may influence theeffectiveness image based services not associated with detecting VLC. Animage may comprise a feature representing a physical feature. In a realenvironment said physical feature may be in view of the camera. Such aphysical feature may be a luminaire comprising edges defining a shape.An image of said physical feature, here the luminaire, may comprise afeature representing said physical feature, i.e. e.g. the edges in theimage defining the shape of the luminaire. The camera may furthercomprise a lens arrangement, which is configured to set a point of focusof the camera, hence the focus of the image. When an object is at thepoint of focus of the lens arrangement, an image of said object will beat its sharpest according to Optics. Any deviation from that point offocus will render a blurrier image. For detecting VLC, a blurrier imagemay be more suitable. Namely, an image of a light source emitting amodulated light signal—e.g. VLC or coded light—may be detected moreeffectively due to the increased footprint of the light source in thecaptured image. However, such ‘out of focus’ may not be suitable foraccurately performing other image based services, which may not beassociated with detecting VLC; because such image based services mayrequire focus to improve the detection of detail. For example, in imageanalytics or object recognition applications said edges of saidluminaire may need to be accurately in focus to determine the shape ofthe luminaire, such that for example the luminaire may be recognized.

Hence, in an embodiment, the image may comprise a feature representing aphysical feature, and wherein the second group of camera settings maycomprise a point of focus set to a distance defined between 90% and 110%of a shortest distance between the camera and the physical feature.Thus, considering the above, said switching according to the inventionis advantageous to improve image based services associated withdetecting VLC and simultaneously improve other image based services notassociated with detecting VLC, both with a single camera. Alternative,said distance may be defined between 95% and 105% of a shortest distancebetween the camera and the physical feature.

In a related embodiment, the image may comprise a feature representing aphysical feature, and wherein the first group of camera settings maycomprise a point of focus set to a distance defined other than between90% and 110% of a shortest distance between the camera and the physicalfeature.

As mentioned, the camera is arranged for capturing an image by capturinga repetitive series of a set of frames, wherein said set of frames maycomprise a first subset of frames and a second subset of frames, whereineach subset may comprise at least one frame; and wherein the processoris configured to switch the camera periodically between the first groupof camera settings and the second group of camera settings for capturingthe image by capturing each first subset of frames of the repetitiveseries of the set of frames with the first group of camera settings andeach second subset of frames of the repetitive series of the set offrames with the second group of camera settings.

The camera may comprise a framerate for recoding the image. Saidframerate is the number of frames per second to capture the image withthe camera. Said framerate may for example be 30 fps or 60 fps, oralternatively be 120 fps in case of e.g. slow-motion capturing, 25 fpsor 50 fps.

The set of frames is repetitive. Thus, the camera is arranged forrecoding an image by capturing a repetitive series of a set of frames.Said set of frames may comprise a first subset of frames and a secondsubset of frames. The processor may set the number of frames in eachsubset.

In an embodiment, said first subset of frames and said second subset offrames may comprise an equal number of frames. Such an equal number offrames may for example be one frame, two frames, three frames or fourframes. Hence, in an embodiment, said first subset of frames maycomprise two frames and the second subset of frames may comprise twoframes. The effect of said equal number of frames is that the set offrames is divided in an equal number of frames for the first subset andthe second subset. Said switching may thus occur per every framecaptured by the camera; or per every two frames, three frames, etc. Asthe set of frames is repetitive, this may render a series wherein thecamera effectively captures the image with the two different groups ofsettings. Consequently, switching per e.g. very frame renders that thecamera effectively captures the image with the first group of settingsin halve the framerate of the framerate of the camera, and the sameapplies to the second group of settings. Switching per e.g. every twoframes renders that the camera effectively captures the image with thefirst group of settings in a quarter of the framerate of the camera, andthe same applies to the second group of settings.

In each set of frames, the first subset of frames and the second subsetof frames may be in arbitrary order within each set of frames of therepetitive series. However, the order may also be set. Hence, in anembodiment, the first subset of frames precedes the second subset offrames. Thus, the first subset of frames precedes the second subset offrames in the set of frames. This facilitates further processing of thecaptured image, as the first subset of frames captured with the group ofcamera settings associated with VLC will structurally precede the secondsubset of frames captured with the group of camera settings notassociated with VLC.

The number of frames in each subset of frames may also be different,i.e. not equal. This may be advantageous as detecting VLC may requiremore frames than an application not associated with detecting VLC, orvice versa. The device may provide such flexibility. Hence, asmentioned, said first subset of frames may comprise a first number offrames and said second subset of frames may comprise a second number offrames; wherein the processor may further be configured to increase ordecrease said first number of frames and/or said second number framesbased on a characteristic detected in the image. As a result, acharacteristic detected in the image may provide a cue for the device tocapture the image with the first and/or second group of settings withhigher and/or lower number of frames. This ensures an adaptive system,that is a device which may advantageously adapt the framerate ofdetecting the image with the first and/or second group of settingsaccordingly.

In an embodiment, the characteristic may be one of: a facial feature, aluminaire, a light source, a movement of an object, a gesture, a person,an emotion, a contour, an edge, a shape, a code, or a locationindicator. For example, based on detecting a face, the second subset maybe set to comprise more frames, i.e. e.g. from one frame initially tothree frames after detecting the face in the image (by image processingmeans).

As mentioned, said first subset of frames may comprise a first number offrames and said second subset of frames may comprise a second number offrames; wherein the processor may further be configured to increase ordecrease said first number of frames and/or said second number framesbased on a sensor input to the device. As a result, a sensor input mayprovide a cue for the device to capture the image with the first and/orsecond group of settings with higher and/or lower number of frames. Thisensures an adaptive system, that is a device which may advantageouslyadapt the framerate of detecting the image with the first and/or secondgroup of settings accordingly. For example, detecting an orientation ofthe device with an orientation sensor, and corresponding sensor input,may cause the device to configure the first subset with a higher numberof frames, as the detected orientation of the device may indicate apriority in using an image based service comprising VLC (e.g. horizontalorientation such that luminaires in a ceiling are detected is anindication of initializing an image based service comprising VLC).

In an embodiment, the sensor input may be one of: a velocity of thedevice, an acceleration of the device, a rotation of the device, anintensity of light detected by the device, a color of light detected bythe device, an audio signal, or a detected position. For example, thesensor input may comprise a detected intensity of light, wherein thelight may be modulated and comprising a code. Thus, the code may be anincentive to increase the number of frames corresponding to the firstsubset of frames. This enables more functionality to the device in imagebased services and an adaptive control thereof.

Hence, in an embodiment, the processor may be configured to increasesaid first number of frames based on detecting a light source. Inanother embodiment, the processor may be configured to increase saidsecond number of frames based on detecting a facial feature.

It is a further object of the invention to provide an improved methodfor image based services. Thereto, the invention further provides amethod for image based services, the method being performed by a devicecomprising a camera and a processor; wherein the camera comprises afirst group of camera settings associated with detecting Visible LightCommunication and a second group of camera settings not associated withdetecting Visible Light Communication; wherein the method comprises thesteps of: capturing an image with the camera by capturing a repetitiveseries of a set of frames, wherein said set of frames comprises a firstsubset of frames and a second subset of frames, wherein each subsetcomprises at least one frame; switching the camera periodically betweenthe first group of camera settings and the second group of camerasettings for capturing the image by capturing each first subset offrames of the repetitive series of the set of frames with the firstgroup of camera settings and each second subset of frames of therepetitive series of the set of frames with the second group of camerasettings; enabling image based services based on at least one frame ofthe first subset of frames and/or at least one frame of the secondsubset of frames; wherein said first subset of frames comprises a firstnumber of frames and said second subset of frames comprises a secondnumber of frames; wherein the method further comprises the step of:increasing or decreasing said first number of frames and/or said secondnumber frames based on a characteristic detected in the image and/orbased on a sensor input to the device.

The method may be performed by the device for image based servicesaccording to the invention. Moreover, the embodiments of the deviceaccording to the invention may mutatis mutandis apply to the methodaccording to the invention.

In an embodiment, said method is provided, wherein the first group ofcamera settings comprises an exposure time of at most 1/1000 seconds,wherein the second group of camera settings comprises an exposure timeof at least 1/1000 seconds.

Thus, as mentioned, said first subset of frames may comprise a firstnumber of frames and said second subset of frames comprises a secondnumber of frames; wherein the method further comprising: increasing ordecreasing said first number of frames and/or said second number framesbased on a characteristic detected in the image.

Thus, as mentioned, said first subset of frames may comprise a firstnumber of frames and said second subset of frames comprises a secondnumber of frames; wherein the method further comprising: increasing ordecreasing said first number of frames and/or said second number framesbased on a sensor input to the device.

Moreover, the embodiments of the device according to the invention maymutatis mutandis apply to the embodiments of the method according to theinvention.

The invention further relates to a computer program product. Hence, theinvention provides a computer program product for a computing device,the computer program product comprising computer program code to performthe method according to the invention when the computer program productis run on a processing unit of the computing device. For example, saidcomputing device may also be the device according to the invention orthe processor provided in the device.

Thus, aspects of the invention may be implemented in a computer programproduct, which may be a collection of computer program instructionsstored on a computer readable storage device which may be executed by acomputer. The instructions of the present invention may be in anyinterpretable or executable code mechanism, including but not limited toscripts, interpretable programs, dynamic link libraries (DLLs) or Javaclasses. The instructions can be provided as complete executableprograms, partial executable programs, as modifications to existingprograms (e.g. updates) or extensions for existing programs (e.g.plugins). Moreover, parts of the processing of the present invention maybe distributed over multiple computers or processors.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further elucidated by means of the schematicnon-limiting drawings:

FIG. 1 depicts schematically a device for image based servicescomprising a camera and a processor.

FIG. 2 depicts schematically a perspective view thereof.

FIG. 3 depicts schematically a repetitive series of a set of frames of acaptured image, wherein said set of frames comprises a first subset offrames and a second subset of frames.

FIG. 4 depicts schematically another repetitive series of a set offrames of a captured image, wherein said set of frames comprises a firstsubset of frames and a second subset of frames.

FIG. 5 depicts schematically a method for image based services accordingto the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 and FIG. 2 depict schematically, by non-limiting example, anembodiment of a device 100 for image based services. Said device 100comprises a camera 101 for capturing an image 200 and a processor 102.The image 200 is being displayed on the display 103 of the device 100.Alternatively, the image 200 does not required to be displayed but maybe processed internally. The camera 101 is a front-facingrolling-shutter camera directed in the same direction the display 103 isdisplaying. The device 100 further comprises a detector 104 being anorientation sensor. The image 200 is being used for image basedservices. Here, the image 200 comprises a typical view from afront-facing camera being used for Indoor Positioning based on VisibleLight Communication, which is a face 202 of a user holding the device100 with VLC enabled luminaires 201 in the background; and at the sametime the image 200 is being used for emotion detection. Alternatively,the image may be used for Augmented Reality, object recognition, imageanalytics, as well or instead of the emotion detection.

Alternatively, the camera may be a global-shutter camera. Alternatively,the camera may be direction in any other direction, e.g. opposite to thefront-facing direction of the device, such as a back-facing camera. Thecamera may even be a 360-degree camera. Here, the device is embodied aspart of a smartphone device, but may alternatively be part of anotherhand-held device, a tablet, a smartwatch, a wearable device, a smartglass, an augmented reality goggle, virtual reality device, heads-updisplay, or a navigation device. The camera 101 comprises a first groupof camera settings 11 associated with detecting Visible LightCommunication, and a second group of camera settings 22 not associatedwith detecting Visible Light Communication. To be more specific, thesecond group of camera settings 22 is being associated with emotiondetection.

Now referring to FIG. 3, the camera 101 captures the image 200 bycapturing a repetitive series 300 of a set of frames 301. Said set offrames 301 comprises a first subset of frames 311 and a second subset offrames 322. Each subset 311, 322 comprises one frame. Hence, both subsetof frames 311, 312 comprise an equal number of frames. Moreover, thefirst subset of frames 311 precedes the second subset of frames 312.Alternatively, each subset comprises at least one frame. The number offrames in both subset of frames 311, 312 may for example be anothervalue, such as 1, 3, 4, 5, or 6, or even 50 or 60.

In alternative embodiments (not depicted), the first subset of framesand the second subset of frames may comprise a different number offrames. For example, the first subset of frames may comprise 2 frames,while the second subset of frames may comprise 1 frame. Othercombinations such as the first subset of frames versus the second subsetof frames being in the number of frames may be equal to 1:2, 1:3, 1:4,1:5, 2:3, 2:4, 2:5, 3:4, 3:5, 4:5, or vice versa.

Still referring to FIG. 1, FIG. 2 and FIG. 3, the device 100 furthercomprises a processor 102. The processor 102 is configured to switch thecamera 101 periodically between the first group of camera settings 11and the second group of camera settings 22 for capturing the image 200.The processor 102 of the device 100 enables this by instructing thecamera 101 to capture each first subset of frames 311 of the repetitiveseries 300 of the set of frames 301 with the first group 11 of camerasettings; and to capture each second subset of frames 322 of therepetitive series 300 of the set of frames 301 with the second group ofcamera settings 22.

Here, the first group of camera settings 11 comprises an exposure time81 of at most 1/1000 seconds. Moreover, the second group of camerasettings 22 comprises an exposure time 82 of at least 1/1000 seconds.Alternatively, said first group of camera settings may comprise anexposure time of at most 1/1500 seconds, at most 1/2000 seconds, at most1/3000 seconds, at most 1/4000 seconds, or between at least 1/2000seconds and at most 1/1000 seconds. Yet Alternatively, said second groupof camera settings may comprise an exposure time of at least 1/800seconds, at least 1/500 seconds, at least 1/250 seconds, at least 1/100seconds, or between at least 1/1000 seconds and at most 1/500 seconds.

Yet alternatively, the first group of camera settings may comprise anexposure time proportional to a symbol clock of the device, the symbolclock being related to detecting the Visible Light Communication duringe.g. the indoor positioning.

In photography, a shorter exposure time renders relatively more contrastbetween bright areas and dark areas within a captured image; a brightfeature such as a light source may therefore become more distinct in theimage in comparison to its surroundings by a decrease in the exposuretime. Such a distinction is advantageous in detecting VLC or coded lightsignals emitted by e.g. a light source.

Referring to FIG. 3, as the first group of camera settings 11 comprisesan exposure time 81 of at most 1/1000 seconds, the first group of camerasettings 11 is particularly suited for detecting VLC. Namely, the image200 captured by the first subset of frames 311 will be underexposed;wherein underexposing typically results in a darkened image in whichonly the bright areas, such as luminaires 201 in the image 200, are moredistinct. Setting the camera 101 to the first group of camera settings11 is therefore a clear advantage for detecting VLC and/or coded light.

However, said first group of camera settings 11 is typically notsuitable for accurately performing other image based services, which maynot be associated with detecting VLC, such as the emotion detection inthe present embodiment; because said underexposure may prevent capturingand/or analyzing details in the image 200 required for emotiondetection, such as the tears 203, 204 of the face 202 of the user in theimage 200. In time, the initial tears 203 intensify in more tears 204and eventually dry up to a happy face 205. Such an emotion change isdifficult to capture with the first group of camera settings 11 due tosaid underexposure and lack of capturing details. Therefore, the cameraof the device according to the invention comprises a second group ofcamera settings 22 not associated with detecting VLC, wherein saidsecond group of camera settings 22 comprises an exposure time 82 of atleast 1/1000 seconds.

As mentioned, the processor 102 is configured to switch the camera 101periodically between the first group of camera settings 11, 81 and thesecond group of camera settings 22, 82 for capturing the image 200.Consequently, the captured image 200 is captured by each first subset offrames 311 of the repetitive series 300 of the set of frames 301 withthe first group of camera settings 11, 81; and by each second subset offrames 322 of the repetitive series 300 of the set of frames 301 withthe second group of camera settings 22, 82. As a result, two differentimage based services, i.e. the one being Indoor Positioning based on VLCand the other being emotion detection, are enabled using a single camera101 comprised within the device 100.

Thus, the processor 102 is enabling improved image based servicesrelated to indoor positioning based on VLC based on the frames capturedwith the first subset of frames 311, as said first subset of frames 311is captured with the first camera settings 11; while enabling imagebased services related to emotion detection based on the frames capturedwith the second subset of frames 322, as said second subset of frames322 is captured with the second camera settings 22.

One application of the device 100 enabling indoor positioning based onVLC and emotion detection simultaneously with a single camera is that anemotion map may be established in a retail environment, wherein indoornavigation is accurately performed due to the first group of camerasettings 11 being particularly suited for detecting VLC (e.g. the VLCemitting luminaires 201), while still be able to detect emotions 203,204, 205 of a user 202 due to the second group of camera settings 22being particularly suited for detecting emotions 203, 204, 205. With theuse of such an emotion map, retailers may be provided with an insight inconsumer interests at various locations and e.g. provide advertisementsaccordingly.

Alternatively, in addition to said exposure time or instead of saidexposure time, the first group of camera settings may comprise an ISOvalue of at least 400, whereas the second group of camera settings maycomprise an ISO value of at most 400. Namely: An ISO value (of a cameradevice) may also influence the effectiveness of detecting VLC, whileadversely influencing the effectiveness of other image based servicesapplications such as emotion detection. Thus, as mentioned, saidswitching according to the invention is advantageous. Yet alternatively,the first group of camera settings comprises an ISO value of at least800, at least 1600, or at least 3200. Yet alternatively, the secondgroup of camera settings comprises an ISO value of at most 400, at most200, at most 100, at most 50, or equal to 50, or an auto ISO notextending beyond a value of 400.

Alternatively, in addition to said exposure time or instead of saidexposure time, the second group of camera settings may comprise a pointof focus, the point of focus being set to the face of the user and notthe luminaires in the ceiling. As a result, the tears of the user may becaptured accordingly, such that emotion detection may be facilitated.Thus, considering the above, said switching according to the inventionis advantageous to improve image based services associated withdetecting VLC and simultaneously improve emotion detection, which isanother image based service not associated with detecting VLC, both witha single camera.

In an alternative embodiment (not depicted), partly similar to theembodiment depicted in FIGS. 1 to 3, but now the detector is configuredto sense an orientation of the device, which is a horizontal orientationwith respect to gravity; hence the horizontal orientation indicating theuse of the device for indoor positioning by means of VLC as the codedlight emitting luminaires are mainly on the ceiling. Upon detecting saidhorizontal orientation, based thereon, the processor increases thenumber of frames in the first subset of frames to three frames, whilekeeping the number of frames in the second subset of frames to a singleframe. Consequently, the relationship between the number of frames inthe first subset compared to the second subset becomes 3:1. Hence, moreframes are available now to capture the image with the first group ofcamera settings, which are associated with detecting VLC and are moresuited for detecting VLC. This is advantageous, because the horizontalorientation of the device already indicates that the relevance of thedevice for use in indoor positioning has become larger compared to e.g.other image based services. Increasing the number of frames in the firstsubset of frames will therefore improve and speed up VLC detection.

FIG. 4 depicts schematically, by non-limiting example, an embodiment ofa device for image based services, which is partly similar to theembodiments depicted in FIG. 1 and FIG. 2, but now the camera capturesthe image 600 by capturing a (different) repetitive series 400 of a setof frames 401. Said set of frames 401 comprises a first subset of frames411 and a second subset of frames 422. The first subset of frames 411comprises one frame. The second subset of frames 422 comprises twoframes. Moreover, the first subset of frames 411 precedes the secondsubset of frames 422.

The image 600 is being used for image based services. Here, the image600 comprises a view of a camera looking at lighting device. The image600 is being used by the device internally for both VLC communicationand Augmented Reality. For the use of Augmented Reality, the position ofthe lighting device edges is required to be identified with imageanalysis, e.g. for establishing anchoring points for Augmented Realityinformation. For the VLC communication, on the contrary, a largefootprint of the light emitted by the lighting device is required.

Similarly mentioned before, the camera comprises a first group of camerasettings 111 associated with detecting Visible Light Communication, anda second group of camera settings 222 not associated with detectingVisible Light Communication. To be more specific, the second group ofcamera settings 222 is being associated with Augmented Reality and imageanalysis.

Still referring to FIG. 4, the device further comprises a processor. Theprocessor is configured to switch the camera periodically between thefirst group of camera settings 111 and the second group of camerasettings 222 for capturing the image 600. The processor of the deviceenables this by instructing the camera to capture each first subset offrames 411 of the repetitive series 400 of the set of frames 401 withthe first group 111 of camera settings; and to capture each secondsubset of frames 422 of the repetitive series 400 of the set of frames401 with the second group of camera settings 222.

Here, the first group of camera settings 111 comprises an exposure time91 of 1/1800 seconds. Moreover, the second group of camera settings 222comprises an exposure time 92 of 1/500 seconds. Furthermore, the firstgroup of camera settings 111 comprises a resolution 71 of 0.5megapixels, whereas the second group of camera settings 222 comprises aresolution 72 of 8 megapixels.

As mentioned, a shorter exposure time renders relatively more contrastbetween bright areas and dark areas within a captured image; a brightfeature such as a light source may therefore become more distinct in theimage in comparison to its surroundings by a decrease in the exposuretime. Such a distinction is advantageous in detecting VLC or coded lightsignals emitted by e.g. a light source.

Referring to FIG. 4, as the first group of camera settings 111 comprisesan exposure time 91 of 1/1800 seconds and a resolution 71 of 0.5megapixels, the first group of camera settings 111 is particularlysuited for detecting VLC. Namely, the image 600 captured by the firstsubset of frames 411 will be underexposed and less resolute. Theunderexposing typically results in a darkened image in which only thebright areas, such as the light emitted by the lighting device 601 inthe image 600, are more distinctly seen. Moreover, the lesser resolutionadditionally causes the footprint (‘blob’) of the light emitted by thelighting device 601 to be seen with an increased size, which largersized footprint may be decoded more effectively and faster (as lesspixels are required to be analyzed with a lower resolution, lessprocessing power is required and less battery power). Setting the camerato the first group of camera settings 111 is therefore a clear advantagefor detecting VLC and/or coded light.

Referring to FIG. 4, as the second group of camera settings 222comprises an exposure time 92 of 1/500 seconds and a resolution 72 of 8megapixels, the second group of camera settings 222 is particularlysuited for detecting details in the image for facilitating AugmentedReality and image analysis. Namely, the image 600 captured by the secondsubset of frames 422 will be overexposed and comprises a highresolution. The overexposure typically results in a bright image whereindetails are clearly visible, such as the edges 602 of the lightingdevice 601 in the image 600. Thus, the lighting device 601 may beidentified and anchoring locations on the lighting device 601 may befound for positioning augmented reality information. This is also anadvantageous effect of the higher resolution. Setting the camera to thesecond group of camera settings 222 is therefore a clear advantage forAugmented Reality applications and image analysis.

As mentioned, the processor is configured to switch the cameraperiodically between the first group of camera settings 111, 91, 71 andthe second group of camera settings 222, 92, 72 for capturing the image600. Consequently, the captured image 600 is captured by each firstsubset of frames 411 of the repetitive series 400 of the set of frames401 with the first group of camera settings 111, 91, 71; and by eachsecond subset of frames 422 of the repetitive series 400 of the set offrames 401 with the second group of camera settings 222, 92, 72. As aresult, two different image based services, i.e. the one being VLCcommunication and the other being Augmented Reality, are enabled andimproved using a single camera comprised within the device according tothe invention.

Furthermore, still referring to the embodiment depicted in FIG. 4, thenumber of frames in each subset of frames 401 may change upon detectionof a characteristic 603 in the image 600. Here, as depicted, theprocessor may process the image 600 and detect/identify/infer that thelighting device comprises a filament type of light bulb, e.g. based onthe shape of said lighting device or visually seeing the filaments.Subsequently, the processor is configured to increase the number offrames of the first subset of frames 411 from one frame to two frames,and to decrease the number of frames of the second subset of frames 422from two frames to one frame. This ensures an adaptive system.

Alternatively, said characteristic may be one of: a facial feature, aluminaire, a light source, a movement of an object, a gesture, a person,an emotion, a contour, an edge, a shape, a code, or a locationindicator. For example, based on detecting a face, the second subset maybe set to comprise more frames, i.e. e.g. from two frames initially tothree frames after detecting the face in the image (by image processingmeans).

FIG. 5 depicts schematically a method 900 for image based servicesaccording to the invention. The method 900 is being performed by adevice comprising a camera and a processor; wherein the camera comprisesa first group of camera settings associated with detecting Visible LightCommunication and a second group of camera settings not associated withdetecting Visible Light Communication, but with object recognition. Thefirst group of camera settings comprises an exposure time of 1/1500seconds, and the second group of camera settings comprises an exposuretime of 1/800 seconds. The method comprises the step 901 of capturing animage with the camera by capturing a repetitive series of a set offrames, wherein said set of frames comprises a first subset of framesand a second subset of frames, wherein each subset comprises at leastone frame. Here, the first subset comprises two frames and the secondsubset comprises two frames. Alternatively, other number of frames maybe comprised by each subset. Subsequently, the method comprises the step902 of switching the camera periodically between the first group ofcamera settings and the second group of camera settings for capturingthe image by capturing each first subset of frames of the repetitiveseries of the set of frames with the first group of camera settings andeach second subset of frames of the repetitive series of the set offrames with the second group of camera settings. This enables that witha single camera both VLC may be detected accordingly, as well as theobject recognition may be performed effectively, as the exposure timefor both image based services is tuned accordingly for the respectivepurpose. Subsequently, the method comprises the step 903 of enablingimage based services based on at least one frame of the first subset offrames and/or at least one frame of second subset of frames. The imagecomprises a person's face. Thus, the method further comprises the stepof 904 increasing said number frames of the second subset of framesbased on a characteristic detected in the image; said characteristicbeing the person's face. Hence, as the device detects in the image thata face is being analyzed, more frames are being used for objectrecognition so as to improve said detection, while keeping the imagesuitable for VLC with the first subset of frames.

Alternatively, the method may comprise increasing or decreasing saidnumber of frames of the first subset of frames and/or said number framesof the second subset of frames based on a sensor input to the device.

The invention claimed is:
 1. A device for image based servicescomprising: a camera for capturing an image by capturing a repetitiveseries of a set of frames; wherein the camera comprises a first group ofcamera settings associated with detecting Visible Light Communicationand a second group of camera settings not associated with detectingVisible Light Communication; wherein said set of frames comprises afirst subset of frames and a second subset of frames, wherein eachsubset comprises at least one frame; a processor configured to: (i)switch the camera periodically between the first group of camerasettings and the second group of camera settings for capturing the imageby capturing each first subset of frames of the repetitive series of theset of frames with the first group of camera settings and each secondsubset of frames of the repetitive series of the set of frames with thesecond group of camera settings; (ii) enable image based services basedon at least one frame of the first subset of frames and/or at least oneframe of the second subset of frames; wherein said first subset offrames comprises a first number of frames and said second subset offrames comprises a second number of frames; wherein the processor isfurther configured to increase or decrease said first number of framesand/or said second number frames responsive to a characteristic detectedin the image, wherein the characteristic in the image provides a cue forthe device to increase or decrease said first number of frames and/orsaid second number frames.
 2. The device according to claim 1, whereinthe characteristic is one of: a facial feature, a luminaire, a lightsource, a movement of an object, a gesture, a person, an emotion, acontour, an edge, a shape, a code, or a location indicator.
 3. Thedevice according to claim 1, wherein the first group of camera settingscomprises an exposure time of at most 1/1000 seconds, wherein the secondgroup of camera settings comprises an exposure time of at least 1/1000seconds.
 4. The device according to claim 1, wherein the first group ofcamera settings comprises an exposure time proportional to a symbolclock of the device, the symbol clock being related to detecting theVisible Light Communication.
 5. The device according to claim 1, whereinthe first group of camera settings comprises an exposure time equal toat least a quarter of a symbol clock of the device, the symbol clockbeing related to detecting the Visible Light Communication.
 6. Thedevice according to claim 1, wherein the first group of camera settingscomprises an ISO value of at least
 400. 7. The device according to claim1, wherein the first group of camera settings comprises a resolution ofat most 1 megapixel, wherein the second group of camera settingscomprises a resolution of at least 1 megapixel.
 8. The device accordingto claim 1, wherein the image comprises a feature representing aphysical feature, and wherein the second group of camera settingscomprises a point of focus set to a distance defined between 90% and110% of a shortest distance between the camera and the physical feature.9. The device according to claim 1, wherein said first subset of framesand said second subset of frames comprise an equal number of frames. 10.A method for image based services, the method being performed by adevice comprising a camera and a processor: wherein the camera comprisesa first group of camera settings associated with detecting Visible LightCommunication and a second group of camera settings not associated withdetecting Visible Light Communication; wherein the method comprises thesteps of: capturing an image with the camera by capturing a repetitiveseries of a set of frames, wherein said set of frames comprises a firstsubset of frames and a second subset of frames, wherein each subsetcomprises at least one frame; switching the camera periodically betweenthe first group of camera settings and the second group of camerasettings for capturing the image by capturing each first subset offrames of the repetitive series of the set of frames with the firstgroup of camera settings and each second subset of frames of therepetitive series of the set of frames with the second group of camerasettings; enabling image based services based on at least one frame ofthe first subset of frames and/or at least one frame of the secondsubset of frames; wherein said first subset of frames comprises a firstnumber of frames and said second subset of frames comprises a secondnumber of frames; wherein the method further comprises the step of:increasing or decreasing said first number of frames and/or said secondnumber frames responsive to a characteristic detected in the image,wherein the characteristic in the image provides a cue for the device toincrease or decrease said first number of frames and/or said secondnumber frames.
 11. The method according to claim 10, wherein thecharacteristic is one of: a facial feature, a luminaire, a light source,a movement of an object, a gesture, a person, an emotion, a contour, anedge, a shape, a code, or a location indicator.
 12. The method accordingto claim 10, wherein the first group of camera settings comprises anexposure time of at most 1/1000 seconds, wherein the second group ofcamera settings comprises an exposure time of at least 1/1000 seconds.13. A non-transitory computer readable medium including a computerprogram product for a computing device, the computer program productcomprising computer program code to perform the method of claim 10 whenthe computer program product is run on a processing unit of thecomputing device.